Insulating-joint.



INSULATING JOINT.

APPLIOATION FILED DEG. 4, 1902.

N0 MODEL.

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Witnesses UNITED STATES Patented May 12, 1903.

' PATENT OFFICE.

JAMES T. ROBB, OF NEW YORK, N. Y., ASSIGNOR TO MITCHELL VANCE COMPANY, OF NEW YORK, N. Y. ,,A' CORPORATION OF NEW YORK.

INSULATING-JOINT.

SPEGIFIGATION forming part of Letters Patent No. 728,015, dated May 12, 1903.

Application filed December 4, 1902. Serial No. 183,878. (No model.)

To all whom it may concern:

Be it known that I, JAMES T. ROBB, a subject of the King of Great Britain, residing at Flatbush, in the borough of Brooklyn, city of New York, State of New York, have invented a certain new and useful Improvement in Insulating-Joints, of which the following is a description.

My invention relates to new and useful improvements in insulatingjoints which are used principally for supporting electric-light fixtures generally from so-called junctionboxes embedded within the ceiling or wall; and my object is to provide an insulating joint which, in the first place, shall be very compact and be capable of direct application within a junction-box, so as to dispense with the employment of separate supporting devices for carrying the joint, which, in the sec 0nd place, shall be extremely strong in construction, so as to be able to carry very heavy fixtures without any danger of accident, which, in the third place, shall be very simple and cheap in construction, owing to the fact that all the insulation used can be formed of sheet-mica, requiring no molding operations, thereby overcoming the use of less efficient and more expensive insulating materials which are required to be used with insulating-joints of other types, and which, in the fourth place, shall be highly efficient in use and shall possess all the characteristics of perfect insulation demanded by the most rigid municipal requirements.

In order that the invention may be better understood, attention is directed to the accompanying drawings, forming a part of this specification, and in which Figure 1 is a vertical sectional view through the insulating-joint in its preferred form and illustrating in dotted lines a junction-box of common type with which the joint may be used; Fig. 2, a horizontal section, and Fig. 3 a side elevation taken at right angles to Fig. 1.

In all of the above views corresponding parts are represented by the same numerals of reference.

The body 1 is formed with two or more integral lugs 2 2 and is preferably cast of any suitable metal. This body is tapered from one end to the other, as shown, and is preferably rectangular in cross-section, as I have indicated in Fig. 2. Mounted Within the body 1 is a tapered head 3, having an integral threaded shank 4. tapered head 3 and the body 1 are sections 5 of insulating material, preferably sheets of mica. The form of these sections is such that they may be conveniently cut out of flat plates of the insulating material without sub- 61 stantial waste, thereby doing away with the necessity of employing the less efiective and more expensive insulating materials which are required with insulating-joints of other types. layer 6 of insulating material, preferably Above the tapered head 3 I place a 65 mica sheets, and the sections 5 and 6 are all held in position by an outer plate 7, secured in place by hollow (preferably copper) rivets 8. Through these rivets the screws or other fastening devices may be passed for securing the joint in position within the junctionbox or elsewhere. Surrounding the shank 4 and covering the exposed contracted end of the body 1 of the device is a layer 9 of insulating material, preferably mica, which is held in place by a nut 10, threaded on the shank 4. By tightening the nut 10 the tapered head 3 will be drawn longitudinally, so as to compress the insulating-sections 5 between the tapered head and the body 1,

while at the same time the insulating layer 9 will be forced tightly against the lower edge of the body 1 and also against the lower edges of the insulating-sections 5, thus firmly securing and binding all the parts together. On the outside of the device I apply a-jacket or shell 11, made of any suitable insulating material molded to the proper form and secured in position by cement. This jacket or go shell is provided with openings through which the lugs or ears 2 extend.

By making an insulating-joint of a generally rectangular form in cross-section, as explained, I am enabled to make effective use of sheets of insulating material, preferably mica, which fill the entire space between the body of the device and the tapered head, so

Intel-posed between the 5 5 that the device is extremely cheap, while at the same time it is of the highest electrical insulating capacity.

All insulating-joints with which I am familiar have either necessitated the use of powdered mica or some similar insulating material having the capacity of being molded, and which, therefore, are not only relatively expensive, but are of less insulating capacity, or else if sheets of insulating material have been used the sheets have been bent around curved forms or in contact with curved surfaces, so as to leave air-spaces, permitting the accumulation of moisture, and therefore destroying the insulating capacity of the device. Furthermore, by making the device of a generally rectangular form in cross-section the threaded shank 4 is effectively prevented from turning in use, which capacity is not present in joints employing shanks having circular heads of common type.

Having now described my invention, what I claim is- 1. As a new article of manufacture, an insulating-joint having a tapered body, a tapered head mounted therein, insulating material between the tapered body and head, a covering-plate, and insulating material between the covering-plate and the tapered head, substantially as set forth.

2. As a new article of manufacture, an insulating-joint having a tapered body, a tapered head mounted therein, insulating material between the tapered body and head, a covering-plate secured in position by hollow rivets, and insulating material between the covering-plate and the tapered head, substantially as set forth.

3. As a new article of manufacture, an insulating-joint having a tapered body, a tapered head mounted therein, insulating material between the tapered body and head, a covering-plate, insulating material between the covering-plate and the tapered head, and an insulating-coating surrounding the sides of the body, substantially as set forth.

4. As a new article of manufacture, an insulating-joint having a tapered body, a tapered head mounted therein, insulating material between the tapered body and head, a covering-plate,-insulating material between the covering-plate and the tapered head, and insulating material covering the contracted end of the body, substantially as set forth.

5. As a new article of manufacture, an insulating-joint comprising a tapered body approximately rectangular in cross-section, a tapered head rectangularin cross-section carrying an integral threaded shank projecting through the reduced end of the body, and sheets of insulating material interposed be tween the tapered head and body, as and for the purposes set forth.

6. As a new article of manufacture, an in sulating-joint comprising a tapered body approximately rectangular in cross-section, a

tapered head rectangular in cross-section carrying an integral threaded shank projecting through the reduced end of the body, sheets of insulating material interposed between the tapered head and body, a covering-plate inclosing the larger end of the head of the body, and insulating material between said covering-plate and the tapered head, as and for the purposes set forth.

7. As a new article of manufacture, an insulating-joint comprising a tapered body approximately rectangular in cross-section, a tapered head rectangular in cross-section carrying an integral threaded shank projecting through the reduced end of the body, sheets of insulating material interposed between the tapered head and body, a covering-plate inclosing the larger end of the body and secured in position by hollow rivets, and insulating material between said covering-plate and the tapered head,as and for the purposes set forth.

8. As a new article of manufacture, an insulating-joint comprising a tapered hollow body essentially rectangular in cross-section, a tapered head essentially rectangular in cross-section within said body and having an integral threaded shank which projects through the reduced end of the body, a covering-plate for the larger end of the body, sheets of insulating material between the tapered head and body and between the covering-plate and head, and an insulating-coating surrounding the exposed sides of the body, as and for the purposes set forth.

9. As a new article of manufacture, an insulatingjoint comprising a tapered hollow body essentially rectangular in cross-section, a tapered head essentially rectangular in cross-section within said body and having an integral threaded shank which projects through the reduced end of the body, a covering-plate for the larger end of the body, sheets of insulating material between the tapered head and body and between the covering-plate and head, and a layer of insulating material covering the contracted end of the body, substantially as set forth.

10. As a new article of manufacture, an insulating-joint comprising a tapered hollow body essentially rectangular in cross-section, a tapered head essentially rectangular in cross-section within said body and having an integral threaded shank which projects through the reduced end of the body, insulating material between the tapered head and body, a layer of insulating material covering the contracted end of the body, and a nut engaging the threaded shank for holding said insulating layer in position, substantially as set forth.

.11. As a new article of manufacture, an insulating-joint comprising a tapered hollow body essentially rectangular in cross-section, a tapered head essentially rectangular in cross-section within said body and having an integral threaded shank which projects through the reduced end of the body, a covering-plate for thelarger end of the body, sheets of insulating material between the tapered head and body and between the covering-plate and head, a layer of insulating material covering the contracted end of the body, a nut engaging the threaded shank for holding said insulating layer in position, and an insulating-coating surrounding the exposed surfaces of the body and also the insulating :0 layer at the reduced end thereof, substantially as set forth. a

This specification signed and witnessed this 15th day of November, 1902.

JAMES T. ROBE.

Witnesses:

CHAS. S. BONNOR, G. O. FERRIs. 

